Two-way prepositions: accusative for motion, dative for rest
The nine German Wechselpräpositionen take the accusative for movement toward a place (wohin?) and the dative for a static location (wo?).
Nine prepositions can take either the accusative or the dative — they are the Wechselpräpositionen: in, an, auf, über, unter, vor, hinter, neben, zwischen.
The case depends on one question:
- Movement toward a goal — wohin? (where to?) → accusative: Ich gehe in die Schule.
- Rest / a fixed location — wo? (where?) → dative: Ich bin in der Schule.
The same preposition, two cases, two meanings. A handy test: if you could ask wohin? and there is a change of place, use the accusative; if you ask wo? and nothing moves, use the dative.
Examples
Ich gehe in die Schule.
I go to school. (movement → accusative)
Ich bin in der Schule.
I am at school. (rest → dative)
Common mistakes
Going to a place is movement (wohin?), so use the accusative die, not the dative der.
Related topics
Practice
Ich gehe in ___ Schule.
Ich bin in ___ Schule.
Das Buch liegt auf ___ Tisch.